FINANCING ARRANGEMENTS (Schedule of Balances Attributable to Notes) (Details) - USD ($) $ in Thousands |
Nov. 30, 2016 |
Feb. 29, 2016 |
May 31, 2015 |
|---|---|---|---|
| Liability component: | |||
| 1.625% convertible senior unsecured notes | $ 145,021 | $ 139,800 | |
| Convertible Senior Notes [Member] | |||
| Liability component: | |||
| Term loan amount | 172,500 | 172,500 | |
| Less: Unamortized debt discount | (24,371) | (29,002) | $ (33,600) |
| Unamortized debt issuance costs | (3,108) | (3,698) | |
| 1.625% convertible senior unsecured notes | $ 145,021 | $ 139,800 |